1. Field of the Invention
The present invention relates to an apparatus and a system for sharing input/output devices by switching between a plurality of computers.
2. Description of the Related Art
Along with the remarkable development of processing performance of computers, use of the computers is becoming more widespread. For example, a personal user may often have a plurality of computers each of which has a different environment. In such case, input/output devices such as a keyboard, a display monitor, and a mouse are typically connected to the plurality of computers with the aim of space and cost saving. Such a switching device is usually called a KVM (K: Keyboard, V: Video, and M: Mouse) switch.
The KVM switch is connected between the input/output devices and the plurality of computers and, simultaneously, functions so that connection of the input/output devices to only any one of the plurality of computers can be active. By using the KVM switch, a user can selectively utilize one computer among the plurality of computers.
Further, at present, as the Internet and an intranet to interconnect plural computers in a network have rapidly become widespread, several computer systems for utilizing the KVM switch have also been proposed.
When a computer is used by connecting it to an external network such as the Internet, there may be problems such as data leakage due to an operating error by a user himself, a cracking attempt or inflow of computer viruses from the external network.
Then, for the purpose of improving security, a computer system has been proposed wherein one computer to be connected to the Internet and the other computer to be utilized personally or to be connected to an intranet are placed separately and are connected to the input/output devices via the KVM switch described above. In such computer system, as the Internet and the intranet are totally separated, a user can selectively use the computer for tasks that do not need the Internet connection or tasks that are especially important, and the other computer for using the Internet connection, depending upon the type or the degree of importance of the tasks.
The computer system where one set of input/output devices controls plural computers via the KVM switch has an advantage in terms of installation cost and space requirement, in comparison with a computer system where each computer has respective input/output devices. However, the former still has several problems.
For example, for the purpose of improvement of the user's working environment, or due to constraints of the working environment, when the KVM switch is disposed near the working desk or other space on which the computers or the input/output devices are placed, the KVM switch may occupy the user's working area unnecessarily.
Further, on the other hand, when the KVM switch is placed in a position that is relatively far from the computers and the input/output devices and not visible to the user, such as space under the working desk or behind the computer, the user's working area may be reserved, but a switching operation or the checking of switching status of the KVM switch may be very inconvenient. Further, the cables for connection between the computers and the input/output devices via the KVM switch may be extended in this case, as a result of which the image quality of the display monitor may be inevitably degraded.
Still further, in terms of improvement of security, it may be preferable to use the plurality of independent computers selectively by means of the KVM switch depending upon the type or the degree of importance of the tasks, but when data is transferred from one computer to the other computer in such computer system, it is inconvenient that the data must be stored temporarily on any storage media, which should be inserted manually into the latter computer.
Therefore, in view of the above problems, it is an object of the present invention to provide a computer and a computer system having security features while reserving the user's working space and reducing installation cost when the input/output devices are shared by switching the plurality of computers.